exp015_ch package (content-bearing heredity: 5 brackets, content gauge, 20 genomes) + repro retrofit: every package standalone (own harness copies, portable data roots, real CLIs, repro.py loaders, genome-aware reader) - all README snippets verified by execution

exp014_gd: genetic distillation + memory substrate — inverse evolution, continuity law, germline fixed point, implant parity; ledger + 23 champion genomes